Women continue to be underrepresented in physical science classes and careers. Hazari et al. tested five hypotheses regarding what factors might affect women's interest: having a single-sex class, having a female teacher, having a female scientist guest speaker, discussing the work of female scientists, and discussing the underrepresentation of women in physics. Based on data from the Persistence Research in Science and Engineering project, which surveyed a sample of over 7000 U.S. college students, individuals were identified as being part of the treatment or control groups by virtue of having experienced, or not experienced, each of the five hypotheses. Next, students were matched so that the females in both treatment and control groups had equal prior physical science career interest, and students were asked to rate the likelihood that they would choose a career in physical sciences. Women who were exposed to discussions about the underrepresentation of women in the physical sciences were more likely to choose a career in physics than those who were not. Such student-centered discussions afford more opportunities for female students to picture themselves as physical scientists. On the other hand, the lack of support for the other hypotheses invalidates the common belief that female role modeling is necessary for attracting women.